1. Field of the Invention
The present invention relates to hair care compositions, and more particularly to hair care compositions such as shampoos, hair rinses, hair conditioners, hair treatments and the like, which contain an alpha-hydroxymonocarboxylic acid or a salt thereof and a specified aromatic alcohol, and which impart long-lasting softness to the hair.
2. Discussion of the Background
Conventionally, hair care compositions contain cationic surfactants such as mono- or di- linear long chain alkyl quaternary ammonium salts or mono- or di- branched long chain alkyl quaternary ammonium salts in an attempt to improve the feel of the hair.
Such conventional hair care compositions, however, have a drawback in that they impart only insufficient softness to the hair, even though they may provide excellent touch to the hair, or they impart excellent moistness and smoothness to the hair due to their conditioning effects. That is, even though the user may feel softness of the hair when it is wet, such effect is mostly lost when the hair is dried. In order to overcome this drawback, use of oils and fats such as higher alcohols, glycerides and liquid paraffins in combination with cationic surfactants has been practiced. This approach is intended to impart softness to the hair by depositing hydrophobic molecules on the surface of hair fibers to lower the surface tension so that the user feels the hair as softened. Such substances deposited on the surface of hair fibers, however, are removed through contact of the fibers in the everyday life or by physical force such as shampooing, and therefore, a prolonged effect of softness is hardly obtained. Moreover, in the case of solid or stiff hair fibers, it often happens that the hair is difficult to manage in obtaining a desired hairdo, and the conventional approach has not met the users' needs.
Recently, in order to enhance the softness of the hair, hair conditioning compositions have been proposed which incorporate a 2-hydroxy aliphatic acid having 6 or more carbon atoms therein as a conditioning component (See, for example, Japanese patent application laid-open (kokai) Nos. 3-48607 and 3-48609). They, however, are not successful in maintaining the softness for a prolonged period.
Accordingly, hair care compositions which are capable of imparting moistness and smoothness to the hair and, at the same time, an excellent long-lasting softness even with solid or stiff hair, while providing easy manageability of the hair for a desired hair care still desired.